T. rex—Fashioned To Be Fearless

Special Dinosaur Section

Contrary to popular portrayals of T. rex as an ungainly
brute who lumbered onto the scene millions of years ago, he was regally designed.
But like lions and other beasts of prey, his deadly behavior became a reminder
of the terrible effects of Adam’s fall. T. rex was fearless.

Tyrannasaurus rex. Just hearing the Latin name evokes power and majesty.
First described in 1905, this “tyrant lizard king” still holds the crown as
the largest and most fearsome terrestrial predator ever discovered in North
America.1

When first created, all the land animals, including dinosaurs, ate only plants
(see “Was Filet Mignon on Eden’s Menu?” pp. 32–34). Other animals had no reason to fear T.
rex, and he certainly had no reason to fear them! But Adam’s Fall shattered
that peace. The Bible does not spell out the specifics of T. rex’s transformation,
but this once-peaceful king become a terror to all who dared to venture into
his domain.2

Since T. rex is found only in Flood deposits, our knowledge of this
great animal is limited to his fossilized remains from Noah’s time, nearly 1,700
years after Adam’s Fall. We’re all fascinated to learn more, and that’s where
the fun of forensic science comes into play. Like crime investigators, paleontologists
try to reconstruct organisms and their environments by the partial evidence
left at the “crime scene.” Though lots of “ifs” remain, we can learn many amazing
things from fossils.

One thing is clear. T. rex was big, and he was well designed for his
dominant role after the Fall. But being big didn’t mean that God just scaled
up the design of other average-size meat-eating dinosaurs, called theropods.
To understand how T. rex was specially designed, we need to compare him
to the “normal” proportions of other theropods.

On a Teeter-Totter

Like all other theropods, T. rex walked and balanced on two legs. They
didn’t walk upright like humans, however, who stand straight up with their spinal
column erect. Instead, the theropod spinal column was horizontal to the ground.
So their long body pivoted on the hips, like the board of a teeter-totter on
its central support.

To properly balance their body, the front end had to be offset by the tail.
To do this, most theropods had a relatively small skull and long arms at the
front end, balanced by a long tail. Now look at the T. rex. His design
displays some fascinating variations on the theropod theme.

First, the skull. Not only is the skull of a T. rex extremely
long (over 4.5 feet, or 1.5 m), it is bulky as well. To lighten the load of
his big head, T. rex had a number of large openings in the bone (called
fenestrae) along the sides and top of the skull.

Muscles were attached along the edges of the fenestrae to give extra strength
to the skull. These muscles also helped to give strength to the jaws and increase
their bite force.

Two eyes on you. The skull was also relatively boxy. Other theropods
had narrower, triangular skulls, with a somewhat limited forward view. The eyes
of T. rex were set into a broad flare toward the back of the skull. So
when T. rex looked down that long snout, he could do so with his eyes
facing fully forward. This suggests that T. rex had excellent stereoscopic
(3-D) vision like you and me.

My, what teeth you have! Of course, if you found yourself staring down
the snout of a T. rex, your gaze would most likely be fixed on his teeth—his
many teeth—his many big teeth. And here we can see another special design
of T. rex.

Most theropod teeth are thin blades, often possessing serrations, like the
edge of a steak knife. While T. rex teeth have small serrations, the
teeth are anything but blade-like. In fact, most T. rex teeth are shaped
more like railroad spikes than knives! The result is a powerful, puncture-style
bite.

When turned against prey, the teeth could be driven in with massive force.
The size of the mouth meant that a direct bite would take out a huge chunk of
flesh. It is unlikely that any animal could withstand the shock and loss of
blood that followed. Even if the T. rex didn’t come in for a second attack,
the animal was most likely a goner.

Tiny arms. Perhaps the most obvious oddity that makes T. rex
appear inelegant is his strangely diminutive arms. The arms aren’t tiny in an
absolute sense (after all, they are the length of an adult human arm), but in
comparison to the body they are, well, puny.

It is here that we must remember how a theropod balances. Head, torso, and
arms must be balanced by tail. To balance such a massive head (weighing a few
hundred pounds!), the tail had to be longer or the arms shorter. The option
that God chose for T. rex is clear: smaller arms and a long tail.

The small size of the arms provides clues about the method T. rex used
to attack and eat his prey. He depended less on his arms than his mouth. After
all, it has been estimated that one direct bite could easily remove 100 pounds
(45 kg) of flesh, so grappling with the prey was probably unnecessary.

But that doesn’t mean that the arms were weak or useless. Amazingly, the arms
appear to have been heavily muscled. Hypotheses about their use range from helping
T. rex rise up from a sleeping position to mating (particularly for males).

Not Your Ordinary Theropod

The largest theropod ever discovered in North America, T. rex was not just
a scaled-up version of smaller, meat-eating theropods. T. rex showcased several
unique designs that enabled him to be kind-sized and exceptional.

Skull:T. rex’s head was massive
and boxy, unlike the relatively slender skulls of other theropods. To reduce
weight, it had numerous openings, called fenestrae.Teeth: Most theropods had blades for teeth, often with serrations like
a steak knife. T. rex had railroad spikes for teeth, capable for driving
down deeply and easily removing as much as 100 pounds (45 kg) of flesh in
one gulp.Eyes: The eyes of most theropods were set in the sides of triangular skulls,
limiting their forward view. But T. rex looked straight forward, with
excellent 3-D vision, because his eyes were set in a broad flare at the back
of his skull.

What’s for Lunch?

So with this kind of arsenal, what exactly did Tyrannosaurus rex hunt
after the Fall? Or was he too big even to hunt at all? Some paleontologists
have argued that T. rex was too big and heavy to run fast enough to catch
prey, and that his blunt teeth and tiny front limbs make more sense for scavenging
rather than active hunting.

More evidence, though, favors a more active predatory behavior. For example,
none of today’s big terrestrial carnivores are pure scavengers. Most big predators
both scavenge and hunt. And if T. rex and his kin weren’t taking down
the large herbivores, who was? The other theropods in the same rock layers as
T. rex are just small fries. If these layers reflect what was in the
same pre-Flood ecosystem, and if T. rex was only a scavenger, then the
large herbivores, such as horn-faced ceratopsians or duck-billed hadrosaurs,
had no large predators.

Another point is that T. rex’s stereoscopic eyesight is great for determining
distance to a target and would have been less necessary for finding corpses
(which obviously don’t move).

T. rex’s sense of smell appears to have been excellent, too. In particular,
the portion of the brain dedicated to smell was greatly enlarged,3 a benefit
for both hunting and scavenging.

Several analyses of the legs and feet of T. rex support modest running
speeds, probably between 11 and 25 mph (18–40 km/h). The more lightly built
juveniles could attain the higher speeds. Based on a discovery of five skeletons
found together in Montana, the juveniles may even have hunted in packs. At these
speeds, which are faster than most human runners, T. rex could easily
match or outrun hadrosaurs and ceratopsians.

Although many puzzles remain, with God’s Word in hand, we are beginning to see even more ways that the Creator has wondrously displayed His power and majesty.

Boosting the argument that T. rex was a predator are potential physical
evidences of failed T. rex attacks. For example, a juvenile Edmontosaurus
(one of the duck-billed dinosaurs) on display at the Denver Museum of Science
and Nature shows some interesting damage to one of the spines of a tail vertebra.
The broken spine displays what appears to be a bite mark that actually healed
over with new bone. Amazingly, one object that fits into the broken spine: a
T. rex tooth!

If this interpretation is correct, then sometime before the Flood, a Tyrannosaurus
rex lunged at the young duck-billed dinosaur. By skill or providence, the
little Edmontosaurus escaped a direct hit, though it bore a scar from
its attacker. Later during the Flood, this animal was catastrophically buried,
hidden underground until it was discovered by scientists.

Although many puzzles remain, with God’s Word in hand, we are beginning to
see even more ways that the Creator has wondrously displayed His power and majesty
throughout the earth (Romans 1:20). His works in the past testify not just to
His creativity and beautiful design but also to “the terror of the Lord” (2
Corinthians 5:11; see Hebrews 12:29).

If we have eyes to see, even this “tyrant lizard king” points us to the true
King and Judge of the earth, who hates sin, who cursed the cosmos because of
Adam’s rebellion, and who will one day judge every sin and right every wrong.

GEOLOGY AND GEOGRAPHY: Found in Upper Cretaceous sedimentary rocks
Known most notably from the Lance Formation (Wyoming) and Hell Creek Formation
(Montana, North Dakota, and South Dakota). Remains also found in Saskatchewan,
Colorado, and New Mexico.

Answers Magazine

October – December 2011

Answers magazine has decided to do some myth-busting. This issue will examine some of the most popular myths about the dinosaurs and how they died. Along the way, you’ll learn some other cool facts about these amazing creatures—quick, can you name the smallest kind of dinosaur? We will also examine some serious contemporary issues, such as the increase of biblical compromise in homeschool materials and the dangers of the new leader in “theistic evolution,” known as the BioLogos Foundation.

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Footnotes

T. rex’s size is eclipsed by two other carnivorous dinosaurs: Spinosaurus
from Africa and Giganotosaurus from South America.

Creationists have suggested several possibilities, but they remain speculative.
See “Design in the Curse,” Answers July–September 2009, p. 30.

The regions of the brain associated with smell are called olfactory bulbs.
Scientists can estimate the size and shape of the brain from the internal cavity
of the skull, and from this, cranial endocasts (internal brain casts) can be
made from injected foam or modeled from MRI and CAT scans.

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Answers in Genesis is an apologetics ministry, dedicated to helping Christians defend their faith and proclaim the gospel of Jesus Christ effectively. We focus on providing answers to questions about the Bible—particularly the book of Genesis—regarding key issues such as creation, evolution, science, and the age of the earth.